P0400
Système
Powertrain (Emissions)
Scanner requis
Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test)

Exhaust Gas Recirculation Flow Malfunction

Understand P0400, common causes, and the right FOXWELL scanner to diagnose it.

General EGR system fault — flow detected when none expected or control circuit issue.

Symptômes courants

  • Rough idle
  • Knock under acceleration
  • Check engine light

Causes typiques

  • Failed EGR valve
  • Carbon blockage
  • Vacuum supply to EGR solenoid
  • DPFE/MAP sensor on Ford EGR

Quel scanner choisir ?

Enhanced OBD2 scanner (live data graphs, freeze frame, battery voltage test)

Utilisez les données en direct et le freeze frame avant de remplacer des pièces. Les codes ABS, SRS et U nécessitent souvent un scanner mult systèmes.

Conseils de diagnostic

  • Enregistrez le freeze frame lors de la première apparition du code
  • Effacez le code uniquement après avoir corrigé la cause
  • Vérifiez les codes en attente associés
  • Vérifiez que la batterie est au-dessus de 12,4 V avant de suspecter un capteur

Scanners FOXWELL recommandés

Questions fréquentes

Can I diagnose P0400 with a basic code reader?
P0400 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Is it safe to drive with P0400?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.